The objective of an invention is the device for safety guiding a hauling chain, especially for a ranging drum shearer for use in coal mining.
Up till now, known structures of chain haulage drives for ranging drum shearers have been equipped with a driving sprocket matching a link chain spanned or circulating along a conveyor route.
Free spanned and unprotected hauling chain, as used in these structures, presents a steady endangering for the team at a coal face. Very often accidents occur due to random chatter or displacement of the chain, caused by dynamic loads or link cracking, when worn or of failure. So there is an endagering space along the hauling chain that disturbs the full yield work of the coal face team. There are also other essential disturbances of the coal face work, such damage or unloading of the face conveyor due to entering the chain into a conveyor chute and by chain banging against timbering, thus reducing its efficiency.
In order to diminish random lateral chatter of the chain, it has been known to use grips and supports to secure the chain at holding posts spaced at 10 to 50 meters along the coal face. Such equipment is commonly attached to the upper part of the conveyor guard along its route. Removable enclosures of most known structures are put on and taken off by hand according to the shearing machine displacement. The enclosures are shaped as tube sections, bent bars, jaws and lever sets, being locked by means of bolts, wedges and latches. Known also are structures to limit the lateral chain movements, formed as levers that close by themselves under gravitation force or prestressed springs built inside the enclosures bodies. Applying separate chain holding devices along the ranging shearer route requires strong structures, resulting in their large overall dimensions and in strengthened posts to fasten them at the route, so they can endure great forces, being a component of the chain tension. This requires organizational and safety rules by working personnel at the coal face to avoid collision of the ranging shearer entering the chain support. The defficiency of these chain enclosures lies also in their low effectiveness at work, because they do not eliminate the lateral chain chatter at distances between two neighbouring supports and create difficulty by exploitation work at the coal face.